A large crystal formed in a metamorphic rock by recrystallization, surrounded by a finer-grained groundmass of other metamorphic crystals; a porphyroblast.
Origin
Early 20th century. From meta- + cryst-, after phenocryst, xenocryst.
Definition of metacryst in US English:
metacryst
nounˈmɛtəkrɪst
Geology
A large crystal formed in a metamorphic rock by recrystallization, surrounded by a finer-grained groundmass of other metamorphic crystals; a porphyroblast.
Origin
Early 20th century. From meta- + cryst-, after phenocryst, xenocryst.